As one component of the "NIH/DC Initiative to Reduce Infant Mortality" a program of research addressing the threat of injuries and neglect to infants and toddlers in the District of Columbia has been developed. The study is divided into two phases. During phase one a comprehensive, city-wide injury surveillance system will be established. This surveillance will include all injuries in the target age group (birth through two years) that result in an emergency room visit, hospitalization or death. Information will also be obtained from the Department of Family Services on substantiated cases of abuse and neglect. The information obtained in phase I will guide the design of specific targeted interventions, for the prevention of injuries, that will be implemented and evaluated in phase II. A randomized intervention trial of local community entities (neighborhoods or wards) is proposed in which epidemiologically-based environmental interventions are applied to one group, behaviorally-based interventions to prevent abuse and neglect are given to a second group, and epidemiologic surveillance alone is conducted in a third group. As an essential component of injury prevention, the injury surveillance system will continue for all three groups, throughout phase II. The remainder of this report focuses on the phase I surveillance activities, as detailed plans for the intervention phase are dependent on the results of the surveillance and thus have not yet been developed.